开发和验证与运动解析重建和基于字典匹配的参数估计相结合的数据采集方案，以实现自由呼吸各向同性分辨率自导航全肝同步水特定 T 1 $$ {\mathrm{T} }_1 $$ ( wT 1 $$ {\mathrm{wT}}_1 $$ ) 和 T 2 $$ {\mathrm{T}}_2 $$ ( wT 2 $$ {\mathrm{wT}}_2 $$ ）映射，用于表征弥漫性和肿瘤性肝病。所提出的数据采集包括磁化准备脉冲和具有径向堆栈星轨迹的双回波梯度回波读数，用不同的准备重复以实现不同的 T 1 $ $ {\mathrm{T}}_1 $$ 和 T 2 $$ {\mathrm{T}}_2 $$ 在 6 min 的固定采集时间中进行对比。使用自导航进行规则化重建，以解释自由呼吸采集期间的运动，然后进行水脂分离。应用序列的 Bloch 模拟来优化 3 T 时 B 1 $$ {B}_1 $$ 不敏感的序列时序，以校正松弛引起的模糊，并映射 T 1 $$ {\mathrm{T}} _1 $$ 和 T 2 $$ {\mathrm{T}}_2 $$ 使用字典。所提出的方法在具有不同松弛特性的水脂模型上进行了验证，并在 10 名志愿者中根据成像和光谱参考值进行了验证。该方法的性能和稳健性在五名患有腹部病变的患者中进行了评估。模拟表明该方法在测量 T 1 $$ {\mathrm{T}}_1 $ 方面具有良好的 B 1 $$ {B}_1 $$ 不敏感性$ 和 T 2 $$ {\mathrm{T}}_2 $$ 值。所提出的方法产生共同配准的 wT 1 $$ {\mathrm{wT}}_1 $$ 和 wT 2 $$ {\mathrm{wT}}_2 $$ 映射，与参考方法非常一致（幻影：wT 1 = 1 . 02 wT 1,ref - 8 . R 2 = 0 .$$ {\mathrm{wT}}_1=1.02\kern0.1em {\mathrm{wT}}_{1,\mathrm{ref }}-8.93\kern0.1em \mathrm{ms},{R}^2=0.991 $$ ; wT 2 = 1 . 03 wT 2,ref 0 . R 2 = 0 {\mathrm {wT}}_2=1.03\kern0.1em {\mathrm{wT}}_{2,\mathrm{ref}} 0.73\kern0.1em \mathrm{ms},{R}^2=0.995 $$ )。所提出的 wT 1 $$ {\mathrm{wT}}_1 $$ 和 wT 2 $$ {\mathrm{wT}}_2 $$ 映射表现出良好的可重复性，并且可以在患有病理的患者中稳健地执行。所提出的方法允许整体-liver wT 1 $$ {\mathrm{wT}}_1 $$ 和 wT 2 $$ {\mathrm{wT}}_2 $$ 在自由呼吸期间在固定采集时间内以各向同性分辨率进行高精度定量。© 2024作者。约翰·威利 (John Wiley) 出版的《生物医学中的核磁共振》

To develop and validate a data acquisition scheme combined with a motion-resolved reconstruction and dictionary-matching-based parameter estimation to enable free-breathing isotropic resolution self-navigated whole-liver simultaneous water-specific T 1 $$ {\mathrm{T}}_1 $$ ( wT 1 $$ {\mathrm{wT}}_1 $$ ) and T 2 $$ {\mathrm{T}}_2 $$ ( wT 2 $$ {\mathrm{wT}}_2 $$ ) mapping for the characterization of diffuse and oncological liver diseases.The proposed data acquisition consists of a magnetization preparation pulse and a two-echo gradient echo readout with a radial stack-of-stars trajectory, repeated with different preparations to achieve different T 1 $$ {\mathrm{T}}_1 $$ and T 2 $$ {\mathrm{T}}_2 $$ contrasts in a fixed acquisition time of 6 min. Regularized reconstruction was performed using self-navigation to account for motion during the free-breathing acquisition, followed by water-fat separation. Bloch simulations of the sequence were applied to optimize the sequence timing for B 1 $$ {B}_1 $$ insensitivity at 3 T, to correct for relaxation-induced blurring, and to map T 1 $$ {\mathrm{T}}_1 $$ and T 2 $$ {\mathrm{T}}_2 $$ using a dictionary. The proposed method was validated on a water-fat phantom with varying relaxation properties and in 10 volunteers against imaging and spectroscopy reference values. The performance and robustness of the proposed method were evaluated in five patients with abdominal pathologies.Simulations demonstrate good B 1 $$ {B}_1 $$ insensitivity of the proposed method in measuring T 1 $$ {\mathrm{T}}_1 $$ and T 2 $$ {\mathrm{T}}_2 $$ values. The proposed method produces co-registered wT 1 $$ {\mathrm{wT}}_1 $$ and wT 2 $$ {\mathrm{wT}}_2 $$ maps with a good agreement with reference methods (phantom: wT 1 = 1 . 02 wT 1,ref - 8 . 93 ms , R 2 = 0 . 991 $$ {\mathrm{wT}}_1=1.02\kern0.1em {\mathrm{wT}}_{1,\mathrm{ref}}-8.93\kern0.1em \mathrm{ms},{R}^2=0.991 $$ ; wT 2 = 1 . 03 wT 2,ref + 0 . 73 ms , R 2 = 0 . 995 $$ {\mathrm{wT}}_2=1.03\kern0.1em {\mathrm{wT}}_{2,\mathrm{ref}}+0.73\kern0.1em \mathrm{ms},{R}^2=0.995 $$ ). The proposed wT 1 $$ {\mathrm{wT}}_1 $$ and wT 2 $$ {\mathrm{wT}}_2 $$ mapping exhibits good repeatability and can be robustly performed in patients with pathologies.The proposed method allows whole-liver wT 1 $$ {\mathrm{wT}}_1 $$ and wT 2 $$ {\mathrm{wT}}_2 $$ quantification with high accuracy at isotropic resolution in a fixed acquisition time during free-breathing.© 2024 The Author(s). NMR in Biomedicine published by John Wiley & Sons Ltd.